The regal pair are in Cheshire today to carry out a series of royal duties from unveiling the Mersey Gateway Bridge to officially opening the local Storyhouse Theatre.

But casting their newfound friendship aside for one moment, it’s their chosen mode of transport which has intrigued the nation.

The Queen and Duchess of Sussex disembark from the royal train on 14 June [Photo: Getty]

The royal pair travelled from London to Cheshire overnight onboard the royal train, a gesture which has never been extended to the Duchess of Cambridge or Prince Harry.

The regal sleepover will have given Meghan Markle ample time to get to know her new grandmother-in-law away from the media spotlight and hints at the flourishing relationship between them.

From the family members who have their own quarters onboard to the history behind the 19th century vehicle, here’s a sneak peek inside the royal train.

When was the royal train first introduced?

The royal train dates back to the mid 19th century and was first commissioned for use by Queen Victoria back in 1842.

An inside view of Queen Victoria’s saloon carriage on display at York railway museum in 1977 [Photo: Getty]

Her Majesty’s great-great grandmother was the first member of the British royal family to ride a train and last year, the Queen re-enacted the then-23-year-old’s debut road trip.

Which members of the royal family can use the royal train?

The royal family has fallen victim to scrutiny on multiple occasions, as a consequence to the high costs of running the train.

According to the Express, the regal mode of transport costs taxpayers £800,000 a year to run which works out at £52 per mile.

The Queen disembarks from the royal train in April 1999 [Photo: Getty]

In a bid to cut costs, the only royals permitted to use the train are the Queen, the Duke of Edinburgh, Prince Charles and the Duchess of Cornwall. It seems Her Majesty eschewed tradition for her new granddaughter-in-law…

What does the royal train look like inside?

With all the pomp and pageantry one would expect from a royal train, there is a total of nine burgundy-hued carriages.

Most of the carriages date back to 1977 when they were used for the Silver Jubilee tours though it is rare that they are all used at one time.

It is possible to move the carriages around in accordance with its intended use and all nine carriages will only be put to use if there are several members of the royal family onboard.

A sneak peek at one of the bedrooms designed for members of staff onboard the train [Photo: Getty]

The train can hold up to 34 people and this can include everyone from Her Majesty’s bodyguards to the Queen’s private secretary.

A photograph of the Queen in her royal headquarters back in 2002 [Photo: Getty]

The carriages also provide accommodation for the royal household staff, police personal protection officers and railway staff members.

Each bedroom has an en-suite bathroom which boasts mahogany toilet seats and sheer plastic shower curtains.

A snapshot of Prince Charles’ suite onboard the royal train [Photo: Getty]

The Queen of course has her own carriage which is reportedly a 75ft long space which includes a formal entrance hall, bedroom, bathroom and seating area.

Adjacent to her carriage is a second lobby area and a room for Her Majesty’s dresser. Despite her large suite, some may be surprised by the less-than-regal interiors.

Back in 2002, director of royal travel, Tim Hewlett, told theBBC: “There is a perception the train is a bit like the Orient Express. But there are not many bathroom furnishings you could not get in Homebase or B&Q.”

Other notable areas onboard include the kitchen and a large 12-seater dining area for the royal family to enjoy breakfast.

The royal meeting room onboard the train [Photo: Getty]

Before Prince Philip retired from his royal duties last year, he also owned a large private quarters onboard the royal train. This included a 10-seat table for the Duke of Edinburgh to hold meetings.

Prince Charles also has his own suite which includes a writing desk, 1960s-style portable radio and images from his private collection.